-62.96% is the change from 81 to 30
Calculation steps:
[( 30 - 81 ) ÷ 81] x 100 = -62.96%
Formula
Percentage change = [(30 - 81) / 81] x 100
Subtract the new number by the original number
30 - 81 = -51
-51 ÷ 81 = -0.6296296296296297
-0.6296296296296297 x 100 = -62.96%